reactions of n-isocyaniminotriphenylphosphorane with cyclopentanone have been studied in the presence of aromatic carboxylic acids and primary amines, proceeds smoothly at room temperature under neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives by an intramolecular aza-wittig cyclization in ch2cl2 in excellent yields. the structures of the products were deduced from...

a highly efficient method for the oxidation of aldehydes to carboxylic acids using polyvinylpolypyrrolidone supported - boron trifluoride (pvpp-bf3) in the presence of 35% hydrogen peroxide has been developed in acetonitrile at 60 °c. this procedure cleanly oxidizes variety of aldehydes to the corresponding carboxylic acids. oxidative esterification of benzaldehyde utilizing pvpp-bf3/h2o2(35%) ...

the esterification of free fatty acids (ffa) with methanol is studied using sulfonated porous carbon (spc) as catalyst. in compare to the amorphous sugar catalyst and protonated nafion, the proposed catalyst shows stability and high efficient performance in biodiesel production. the highest initial rate of oleic acid conversion is obtained at catalyst loading of 1 mmol h+ and mole ratio of meoh...

objectives: the objective of this research was to investigate the chemical composition and antibacterial activities of the fatty acids and essential oil from various parts of ligularia persica boiss (l. persica) growing wild in north of iran. materials and methods: essential oils were extracted by using clevenger-type apparatus. antibacterial activity was tested on two gram-positive and two gra...

boraginaceae family is known as a medicinal plant classified in dicotyledons.  it is originated from asia (middle east). the aim of this study was to evaluate ingredient between 4 species of boraginaceae family based on physiological & phytochemical traits as well as seed fatty acid contents.  4 species (e. russicum, e. italicum, e. amoenum, and b. officinalis ) were evaluated carefully. all se...

a superhydrophobic aluminum surface was fabricated through an enhanced low-cost approach and the effects of several relevant factors on static contact angle and sliding angle were investigated. first, the operating parameters including the etching time as well as the reaction time and temperature were varied. next, the so-called chemical factors including three different fatty acids and five di...

objective: evaluating the effect of dentin conditioning with edta on microleakage of composite resin restorations, using two etch and rinse and two self-etch adhesives. materials and methods: one hundred and sixty extracted molars received class v cavity preparations right under the cej and were randomly divided into eight groups of 20, usingfour different adhesive systems. these adhesives incl...

chamomile (matricaria chamomilla l.) is one of the most important medicinal plants in iran. the main objective of this study was to determine the effects of organic nutrients on the yield and oil content of chamomile. the experiment was conducted in the spring of 2010. the treatment groups consisted of vermicompost (0, 5, 10, 15 and 20 tons/ha) and the aminol forte sprays (no spraying or contro...

Low and high intake of fat consumption regardless of its kind can jeopardize personal and public health. Despite the importance of quality and quantity of fat in the diet and its relationship with some chronic disorders such as coronary heart disease, some types of cancers, obesity and diabetes, the consumption pattern of fats and their . constituent fatty acids have not yet been assessed in ou...